Elemental Analysis of Glass and Ink by Laser Ablation Inductively
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Florida International University FIU Digital Commons FIU Electronic Theses and Dissertations University Graduate School 3-30-2009 Elemental Analysis of Glass and Ink by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Laser Induced Breakdown Spectroscopy (LIBS) Benjamin E. Naes Florida International University, [email protected] DOI: 10.25148/etd.FI10022536 Follow this and additional works at: https://digitalcommons.fiu.edu/etd Recommended Citation Naes, Benjamin E., "Elemental Analysis of Glass and Ink by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP- MS) and Laser Induced Breakdown Spectroscopy (LIBS)" (2009). FIU Electronic Theses and Dissertations. 207. https://digitalcommons.fiu.edu/etd/207 This work is brought to you for free and open access by the University Graduate School at FIU Digital Commons. It has been accepted for inclusion in FIU Electronic Theses and Dissertations by an authorized administrator of FIU Digital Commons. For more information, please contact [email protected]. FLORIDA INTERNATIONAL UNIVERSITY Miami, Florida ELEMENTAL ANALYSIS OF GLASS AND INK BY LASER ABLATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (LA-ICP-MS) AND LASER INDUCED BREAKDOWN SPECTROSCOPY (LIBS) A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in CHEMISTRY by Benjamin E Naes 2009 To: Dean Kenneth Furton College of Arts and Sciences This dissertation, written by Benjamin E Naes, and entitled Elemental Analysis of Glass and Ink by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Laser Induced Breakdown Spectroscopy (LIBS), having been approved in respect to style and intellectual content, is referred to you for judgment. We have read this dissertation and recommend that it be approved. Yong Cai Bruce McCord Andrew Macfarlane Alexander Mebel José R. Almirall, Major Professor Date of Defense: March 30, 2009 The dissertation of Benjamin E Naes is approved. Dean Kenneth Furton College of Arts and Sciences Dean George Walker University Graduate School Florida International University, 2009 ii © Copyright 2009 by Benjamin E Naes All rights reserved. iii DEDICATION To my parents Roger and Toni and for my wife, Jennifer and our late baby daughter Lilly, who provided much of the inspiration behind the body of work presented here. Without my family and their support through the most difficult of times (rest in peace Lillian Emily Naes), I may not have succeeded and likely would have given up. Therefore, I share my success with them, whom I admire and love dearly. iv ACKNOWLEDGMENTS First and foremost I want to acknowledge my wife and my family for their undying support throughout this journey…what a journey it has been. Furthermore, I give praise to God, who has always channeled my life in an amazing and fulfilling fashion. In addition, I would like to express my gratitude to my graduate committee: Dr. José R. Almirall, Dr. Yong Cai, Dr. Bruce McCord, Dr. Alexander Mebel, and Dr. Andrew Macfarlane for their guidance and support. I especially would like to thank Dr. José Almirall for offering me the opportunity to work in his research group and for supporting my endeavors in and out of FIU; his guidance and wisdom has helped make me into the student I am today. I would like to acknowledge FIU, the Department of Chemistry and Biochemistry, the International Research Forensic Institute, the Dean’s office, and the Graduate Student Association for all the support, funding, etc. over the past 4+ years. Without their support, I would not have been able to expand my knowledge base nor see many of the places that I have while representing FIU at numerous academic conferences. The LIBS study for the forensic analysis of glass was supported by the National Institute of Justice (NIJ), grant 2005-IJ-CX-K069, and thus that is an important acknowledgement. I have to personally thank those who have collaborated with me on the various projects that I undertook, the extended list includes Dr. Jhanis Gonzalez and Dr. Richard Russo at the Lawrence Berkeley National Laboratory, Dr. Cleon Barnett (former post doc) now at Alabama State University, Scott Ryland at the Florida Department of Law Enforcement, Sayuri Umpierrez (former Almirall group member and part of the Miami Dade Crime Lab), and Robert Romanowski at the United States Secret Service. v Additionally, I would like to thank Tatiana Trejos and Yaribey Rodriguez for their help with the ink project and for continuing where my work has ceased. Finally, I would like to thank all present and past Almirall group members that already have not been mentioned. The list includes: María Angelica Mendoza-Baez, Waleska Castro, Monica Joshi, Patricia Guerra, Hanh Lai, Erica Cahoon, Maria Perez, Jenny Gallo, Joseph Gagnon, Howard Holness, Jeannette Perr, and Steven Wise. I thank them for their friendship and support at the various stages in my research and throughout the dissertation process as a whole. My apologies if I left anyone off this list or failed to mention someone, it was entirely unintentional. vi ABSTRACT OF THE DISSERTATION ELEMENTAL ANALYSIS OF GLASS AND INK BY LASER ABLATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (LA-ICP-MS) AND LASER INDUCED BREAKDOWN SPECTROSCOPY (LIBS) by Benjamin E Naes Florida International University, 2009 Miami, Florida Professor José R. Almirall, Major Professor The necessity of elemental analysis techniques to solve forensic problems continues to expand as the samples collected from crime scenes grow in complexity. Laser ablation ICP-MS (LA-ICP-MS) has been shown to provide a high degree of discrimination between samples that originate from different sources. In the first part of this research, two laser ablation ICP-MS systems were compared, one using a nanosecond laser and another a femtosecond laser source for the forensic analysis of glass. The results showed that femtosecond LA-ICP-MS did not provide significant improvements in terms of accuracy, precision and discrimination, however femtosecond LA-ICP-MS did provide lower detection limits. In addition, it was determined that even for femtosecond LA-ICP-MS an internal standard should be utilized to obtain accurate analytical results for glass analyses. In the second part, a method using laser induced breakdown spectroscopy (LIBS) for the forensic analysis of glass was shown to provide excellent discrimination for a vii glass set consisting of 41 automotive fragments. The discrimination power was compared to two of the leading elemental analysis techniques, µXRF and LA-ICP-MS, and the results were similar; all methods generated >99% discrimination and the pairs found indistinguishable were similar. An extensive data analysis approach for LIBS glass analyses was developed to minimize Type I and II errors en route to a recommendation of 10 ratios to be used for glass comparisons. Finally, a LA-ICP-MS method for the qualitative analysis and discrimination of gel ink sources was developed and tested for a set of ink samples. In the first discrimination study, qualitative analysis was used to obtain 95.6% discrimination for a blind study consisting of 45 black gel ink samples provided by the United States Secret Service. A 0.4% false exclusion (Type I) error rate and a 3.9% false inclusion (Type II) error rate was obtained for this discrimination study. In the second discrimination study, 99% discrimination power was achieved for a black gel ink pen set consisting of 24 self collected samples. The two pairs found to be indistinguishable came from the same source of origin (the same manufacturer and type of pen purchased in different locations). It was also found that gel ink from the same pen, regardless of the age, was indistinguishable as were gel ink pens (four pens) originating from the same pack. viii TABLE OF CONTENTS CHAPTER PAGE 1 INTRODUCTION....................................................................................................... 1 1.1 Significance of the Study ..................................................................................... 3 2 ANALYTICAL COMPARISON OF NANOSECOND AND FEMTOSECOND LA-ICP-MS FOR THE ELEMENTAL ANALYSIS OF GLASS ..................................... 5 2.1 Glass Matrix......................................................................................................... 5 2.2 Elemental Analysis of Glass ................................................................................ 7 2.3 Methodology ...................................................................................................... 11 2.3.1 Instrumentation............................................................................................... 11 2.3.1.1 Introduction.............................................................................................. 11 2.3.1.2 Laser Ablation Principles and Considerations......................................... 11 2.3.1.2.1 Advantages of Laser Ablation........................................................... 14 2.3.1.2.2 Disadvantages of Laser Ablation ...................................................... 15 2.3.1.2.3 Femtosecond Laser Ablation............................................................. 17 2.3.1.3 Laser Ablation Systems Description........................................................ 20 2.3.1.3.1 Nanosecond Laser Ablation .............................................................. 20 2.3.1.3.2 Femtosecond Laser Ablation............................................................. 21